The pivotal distinction lies in where embryo development occurs: MOET matures and fertilises embryos inside the donor cow, while IVF accomplishes this in a lab setting. Good quality oocytes selected at the right time of development play a crucial role in successful outcomes.³  The central hurdle in assisted reproduction is consistently producing high-quality oocytes that can develop into healthy, implantable embryos.⁴ 

 

Enhancing Embryo Yield: The Role of FSH

 

Using Follicle Stimulating Hormone in IVF protocols elevates more than just oocyte counts – it enriches oocyte quality, fortifying them for successful fertilisation and subsequent development into blastocysts³. This enhancement is due to the critical role of FSH in synchronising follicular growth, thus yielding oocytes at their optimal developmental stage, leading to more uniform and competent embryos. 

 

Although producers often select MOET due to the higher number of viable embryos collected from a single flush and the higher conception rate of implanted embryos, strategic use of FSH in IVF programs may offer similar advantages.⁵

 

 

Real-world studies back the benefits of FSH, showing a significant 55% boost in viable embryo production with FSH-enhanced IVF, as opposed to standard protocols.⁸ AETA’s findings echo this, indicating substantial gains in embryo viability -- 68% in beef cattle and an impressive 105% in dairy cattle, highlighting FSH’s significant role.⁹ Such evidence firmly establishes FSH as a key factor in modern IVF programs, offering benefits that rival traditional MOET outcomes. 

 

The success of FSH in IVF also varies with cattle breeds, underlying the need for breed-specific strategies when choosing reproductive technologies. For instance, Bos indicus breeds excel in IVF settings, yielding 2 to 3 times more oocytes per IVF collection than Bos taurus breeds.¹⁰ This higher oocyte production makes IVF particularly cost-effective for Bos indicus, pointing to the necessity of a customised approach in reproductive technique selection to align with specific breed attributes.

 

Strategic Selection

 

Selecting the right reproductive technology for a herd or individual animals requires a balanced consideration of the benefits and limitations inherent in IVF, FSH-stimulated IVF and MOET. The increased adoption of IVF in the Americas is attributed to its ability to generate viable embryos in a shorter time frame than MOET. This is largely because IVF permits oocyte collection at frequent intervals – every 7 to 14 days – unlike the extended 30 to 60-day cycles necessitated by MOET, which requires hormonal treatments for superovulation and in-cow embryo production.^1,2 

 

IVF’s direct oocyte retrieval from the ovaries streamlines the process, circumventing the need for donor cycle synchronisation and in vivo maturation, making it advantageous in situations where MOET is not viable, such as with young heifers, non-responsive donors, pregnant cattle or when only post-mortem ovaries are available.² Furthermore, IVF’s flexibility in semen utilisation – allowing for a single semen sample across multiple donors or varying different bulls’ semen on a single donor’s eggs – maximises the use of elite genetic resources and is compatible with sex-sorting semen techniques. ^2,11 

 

Although IVF has these operational flexibilities, MOET still maintains a higher reported conception rate ranging from 8 to 27.8% higher than IVF, which can be a deciding factor for many producers.^5,12 It is crucial to acknowledge that all breeding methods have inherent risks, such as the embryo’s developing environment influencing the postnatal phenotype.^1,13 For instance, 3% of calves born through IVF have been linked to large offspring syndrome, a condition also seen, though less frequently, with MOET and artificial insemination.¹³ 

 

The necessity for specialised equipment and laboratory expertise for IVF also adds a layer of complexity and cost that are less of a concern with MOET, which relies on the natural biological processes of the cow. 

 

 

According to Ced, Australia’s expansive geography can pose significant practical and economic challenges for IVF given “Oocytes must reach the lab within 22 hours of collection, and the resultant embryos must be implanted on the same day they leave the lab. In addition, more than 20 donors may be needed to make an IVF program commercially viable, whereas only one donor is needed with MOET.”

 

Regardless of modality, Ced also emphasises the importance of
a. fertility and recipient management which he believes are responsible for the biggest variations in pregnancy rates. Producers who start with the most fertile cows in the mob, accurately administer synchronisation drugs and ensure there is optimal nutrition in the two months pre- and post implantation are more likely to achieve optimal outcomes; and
b. maximising pregnancies given the cost of running empty recipients can represent the biggest cost to a MOET or IVF program.

 

 

 

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